Some global navigation satellite systems, such as the global positioning system (GPS), the GALILEO system, the BEIDOU system and the quazi-zenith satellite system (QZSS), utilize satellites that broadcast their respective signals on the same carrier frequency in a particular satellite band, but with different pseudo-random (PRN) codes. However, the Russian GLONASS system utilizes satellites that transmit their respective signals with the same PRN code, but on different frequencies within a given satellite band using frequency division multiple access (FDMA). Due to FDMA, inter-frequency bias (IFB) from the GLONASS signals exists on both the code phase and carrier phase measurements in the satellite receiver. The presence of IFB can degrade the accuracy of integer ambiguity resolution when processing the received GLONASS satellite signals to determine position estimates.
Wherever possible, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts, elements, etc. In any of the drawings of this document, any arrow or line that connects any blocks, components, modules, multiplexers, memory, data storage, accumulators, data processors, electronic components, oscillators, signal generators, or other electronic or software modules may include one or more of the following items: a physical path of electrical signals, a physical path of an electromagnetic signal, a logical path for data, one or more data buses, a circuit board trace, and/or a transmission line; a link, a call, communication, and/or data message(s) between software modules, programs, data, and/or components; transmission and/or reception of data messages, software instructions, modules, subroutines and/or components, etc.